Tensile Fracture of Laminates with Holes

Abstract

The methods currently used for predicting static fracture of notched composite laminates in tension, such as the point and average stress criteria and the inherent flaw criterion, are of semi-empirical nature and have limited applicability with respect to size and shape of the notch. In this paper, a damage zone analysis, based on more fundamental concepts, is used to predict fracture of laminates with circular holes of various radii, and oval and rectangular holes of various sizes. The damage is represented by a linear cohesive zone. Based on the two fundamental parameters unnotched tensile strength (σ 0 ) and apparent fracture energy (G* c ), this model excellently predicts the strength of notched laminates for a number of specimens tested.

Comparison of open hole tension characteristics of high strength glass and carbon fibre-reinforced composite materials

“…Generally, carbon fibre-reinforced plastics (CFRP) have been the composite material of choice for use in primary structures due to their high specific strength and modulus. As such, a considerable literature exists on the damage characteristics of notched CFRP laminates [2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17].…”

Assessment of asymmetric crack initiation in open‐hole plates using a coupled stress and energy criterion

“…The hat denotes quantities from the reference FEA. The FFM model is compared against a finite element cohesive zone model (CZM), which proved to provide reliable failure load predictions for uniaxially loaded open-hole plates [5]. The model uses a stress based criterion in order to determine …”

Progressive damage and failure strength of notched woven fabric composites under axial loading with varying strain rates

“…Some researcher conducted experimental tests to further understand the notch failure under tension [10][11][12] as well as under compression [13,14]. A study showed that the load-strain behavior by the hole edge becomes nonlinear at about half the fracture load for carbon/epoxy composites, which suggests that damage initiates at this load level resulting in a more compliant material [10].…”

“…A study showed that the load-strain behavior by the hole edge becomes nonlinear at about half the fracture load for carbon/epoxy composites, which suggests that damage initiates at this load level resulting in a more compliant material [10]. Another study found that the correlation drawn between the notch strength and the characteristic length was that the characteristic length decreased as the notched strength increased [12].…”